Process for producing aldol.



TED STATES PATENT OFFICE.-

RICHARD BLAIR EABLE AND LUCAS IPETRON KYRIAKIDES, OF CAMBRIDGE, MASSA- CHUSETTS, ASSIGNORS 'IO HOOD RUBBER 00., A CORPORATION OF MASSACHUSETTS.

J PROCESS FOR PRODUCING ALDOL.

No Drawing.

Specification of Letters Patent.

Patented Apr. 21, 1914.

Serial No. 685,295.

To all whom it may concern. f

Be it known that we, RICHARD B. 'EARLE and Lucas P. KYRIAKIDEs, citizcnsof the United States, residing at 'Ca rnbridge, Massachusetts, have invented certain new and usefullmprovements in Processes for Producing Aldol, of which the following is a specification. j Our invention relates to a newand valuable process for producing aldol,

cri erion-Ca one),

{i-oxybutyraldehyde, which is a valuable aldehyde useful for the preparation of substances useful for pharmaceutical and technical purposes.

The new process consists in allowing liquid acetaldehyde (CH CHO) to come in contact for a short time withsolid alkaline substances which are insoluble or only slightly soluble in the same, drawing oif the liquid aldehydes and bringing fresh aldehyde in contact with the alkaline condens-' alkaline or alkaline earth hydrates or carbonates, disodium hydrogen phosphate, borax or alkaline sulfites. 1

In order to illustrate the new process more fully the following example is given: The, apparatus is constructed on the principle of a Soxhlet extractor and needs little description. Dry acetaldehyde is boiled in a suitable vessel and thevapors are condensed by a suitable upright condenser. The condensed acetaldehyde drips into a chamber filled with dry slaked lime and when the liquid reaches a level corresponding to the top of the siphon with which the chamber is provided, it is emptied from the I bottom, the liquid being carried back to the vessel in which the .acetaldehyde is boiled. Thus the aldehyde is submitted intermittently to the action of the slaked lime, and

a plicat on filed March 21, 1912.

as aldol possesses a high. boiling point it does not pass up again with the vapors of the aldehyde, so that the concentration of aldol in the acetaldehyde continually increases. As the liquid is only subjected to the action of the slaked lime for a-short period any secondary actions are avoided. After a time the vessel contains a very concentrated solution of aldol which is easily obtained pure by distilling off the acetaldehyde' and any paraldehyde which may be also formed. Any lime carried over mechanically may be neutralized by providing the vessel with suitable neutralizing agents.

The reaction is a condensation of acetaldehyde with itself, as

oH,cHo+oH,oHo= t woi onon ono.

If carried out under suitable conditions so .that no acetaldehyde is lost by evaporation,

the yield is nearly theoretical.

We claim 1. The process of roducing aldol which consists in repeatedly bringing liquid acetaldehyde in contact with calcium hydrate.

2. The process of producing aldol which consists 1n repeatedly bringing acetaldehyde in contact with an alkaline condensing agent.

3. The herein described method of producing aldol which consists in vaporizing 'acetaldehyde, condensing the vapors and bringing the same into contact with a dry alkaline agent, withdrawing the liquid from said agent, and reevaporating the acetaldehyde in said liquid and continuing the process until a concentrated solution of aldol is secured.

' 4. The herein described method of producing aldol 'which consists in vaporizing acetaldehyde, condensing the vapors and bringing the same into contact with dry slaked lime, withdrawing the liquid from said lime, and reevaporating the acetaldehyde in said liquid and continuing the process until a concentrated solution of aldol is secured.

In testimony whereof, we afiix our signatures in presence of two witnesses.

RICHARD BLAIR EARLE.

' LUCAS PETRON KYRIAKIDES. Witnesses:

i J. R. Mo'r'r,

M. A. HACARTY. 

